In 1967, a series of large-scale riots erupted in Hong Kong, causing social instability. These events led some of the richer Hong Kong residents to move abroad. Emigration took place to countries in Southeast Asia, South Africa or South American countries. This wave did not come to a rest until the mid-1970s.

Some people had relocated overseas through studying abroad and staying after graduation, while others simply obtained returning residency visa from the destination country, which was issued by some countries with no conditions attached in the late 1980s, and then returned to Hong Kong. Informed estimates range from 250,000 to one million people, with the peak years of outflow between 1988 and 1994 of about 55,000 per year. In 2011, the estimated migration rate reach the peak. In Hong Kong, over 65 percent of Hong Kong permanent residents desired to migrate to others countries, in accordance with the questionnaires originated from Chinese University of Hong Kong.

In 1990, the outflow of people reached a peak of 62,000 people or about 1% of the population. The emigration rate would reach the peak in 1992 with 66,000 people, followed by 53,000 in 1993, and 62,000 in 1994. An estimated US $4.2 billion flowed from Hong Kong to Canada directly as a result.[2]

From 1998, one year after the transfer of sovereignty, some Hong Kong-born emigrants returned to Hong Kong with foreign citizenship. The phenomenon is called "香港回流潮" (Hong-Kong returning tidal flow).